I upgraded to a newer Nevada build, and Solaris began to panic.
On 104 and v4.1 Build 1051 I had no problems, noce I upgraded to 114, the system crashed when loading the audio driver.
I booted to failsafe, removed the oss package, and since 1052 came out I gave that a try, but no luck.
At install, when the newly installed driver tries to attach (I'm not absolutely sure it happens at that moment), the system panics, and dumps a core in /var/crash, see the stacks at the end.
Nothing has changed in my system, it was a simple live update.